First Ever Performance-Based Comparative Water Use Rating Tool for Home Builders

January 20, 2015 – The Green Builder® Coalition, in cooperation with Build Green New Mexico (BGNM), Santa Fe Area Home Builders Association (SFAHBA), and members of the City of Santa Fe Water Conservation Committee (SFWCC) has created water modeling software that generates a Water Efficiency Rating Score, or WERS. This first-ever industry tool provides a performance-based approach to home builders, while providing home owners a rating to compare water use.

How it Works

Much research was done to calculate the loading from the main plumbing fixtures, clothes washers and pipe priming and their impact on the WERS. For the pilot, only indoor water use is calculated empirically based on the estimated loading of the above items taking into account their associated efficiencies. Rainwater and greywater catchment are also calculated. Depending on the verified filtration methods, they can be used to offset indoor water use much like solar panels can be used to offset energy use in the HERS index. Additionally, any remaining unused rainwater or greywater can be credited to potential outdoor use as an innovative practice.

Other aspects of the WERS program include points for "Innovative Practices". It is envisioned that communities will select a minimum point threshold of Innovative Practices that need to be accomplished as part of the WERS program.

“The 0 to 100 scale of the WERS program plays right into the competitive nature of builders and the marketplace," says Kim Shanahan, Executive Officer of the SFAHBA. "Consumers can easily assess the most water efficient home. A performance-based metric always produces better results than a purely prescriptive standard. It drives innovation and best practices that are quickly adopted by others.”

Project teams have the ability to do initial estimates of the results of their proposed designs. For a WERS rating the project team will send the completed program document to a qualified third-party verifier who will then check fixtures, appliances, and strategies have been installed or implemented as claimed. Once the program document has been verified, it is sent to The Coalition for certification. The certification document will then be utilized by the project team to apply for applicable water conservation tax credits or incentives that require third-party verification.

The Market Effect and Relevance

Most product manufacturers of water fixtures and appliances are already well aware of the multitude of green home building programs, as well as the EPA WaterSense program. Many have responded by providing products that comply with these programs. As the WERS continues to develop nationally and incorporates items that for now are only considered innovative practices, manufacturers may want to consider following news regarding the program. Information is available by signing up for the Green Builder® Coalition's communications and soon on the official WERS website, www.wers.us.

"Having a ‘performance path’ for water will help transform the building industry in the same way that the HERS index did for energy”, says Steve Hale, Program Director for BGNM. "Already, we are seeing much better performing fixtures and appliances. Now, with the ability to ‘mix and match’ flow rates while simultaneously examining the overall performance of indoor water use, builders and consumers can make smart choices for the products they put into their homes."

Next Steps

The program continues to be developed under the tutelage of several industry stakeholders and has already been piloted within the State of New Mexico. Now that the WERS is available, new legislation sponsored by Senator Peter Wirth has been proposed and will be introduced in the New Mexico Senate legislature this year. The intent is to add water efficiency to the existing Sustainable Building Tax Credit legislation. Additionally, The Coalition is working with Santa Fe Community College to begin a training program for use of the WERS program, verification procedures, and certification.

The Coalition is seeking input from other municipalities that are interested in evaluating and potentially using this tool. “We’re very proud of the inaugural version of WERS,” said Green Builder® Coalition Executive Director Mike Collignon. “Now that we’ve completed that work, we’re interested in collaborating with other municipalities who have a need or interest in conserving water. The WERS program can be valuable to those communities as either an incentive or regulation. We’re also forming a national committee to help us with the next iteration of the WERS program, where we’ll look to expand the outdoor portion.”

About Green Builder® Coalition - The Green Builder® Coalition is a not-for-profit association dedicated to amplifying the voice of green builders and professionals to drive advocacy, information and education for more sustainable home building practices. We are an action-oriented community of green builders and professionals dedicated to uniting and growing our joint expertise, values and voice to create stronger standards for sustainable, more environmentally responsible home building. For more information, visit www.greenbuildercoalition.org.

About Build Green New Mexico - Build Green NM is an education and certification program for building High Performance Homes across the State of New Mexico. High performance means added comfort, lower utility bills and healthier indoor air quality to name a few of the key features. We don't build great homes; we certify them from experienced builders across the state. Added in 2015 is a complementary program regarding efficiency upgrades to existing homes. For more information, please visit www.BuildGreenNM.com.

About Santa Fe Area Home Builders Association - As a local Home Builders Association in one of America’s most progressive and green-focused communities, SFAHBA proudly reflects its local demographic and constantly pushes the envelope in re-imagining the built environment. With national lab scientists, world-renowned artists, and indigenous cultures going back centuries and millennia, Santa Fe builders have many sources of inspiration to draw upon. Their creative thinking on water, energy, and resource efficiency finds its way into the unique homes that embody “Santa Fe Style”. For more information, visit www.sfahba.com.